Improved iron truss-bridge



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GEORG@ HALSTEAD, OF BUFFALO, NEW YORK.

15mm Patent N0. 91,124, aand .Tutev s, 1869.

DPROVED IRON MUSS-BRIDGE.

The Schedule referred to :in thelc'Lettei-n Patent and making part of the name.

To all whom it may concern:

Be it known that I, GEORGE HALSTEAD, of the city of Bn'alo, in the county of Erie, and State of New York, have invented certain new and useful Improvements in Iron Truss-Bridges; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification.

The nature of my invention consists- First, in constructing a truss-block to receive and secure the diagonal tie-rods with a contour, such as last stated, and in addition thereto with upward projections overlapping the upper iianges ofthe chordbeams, and fashioned to receive and secure against lateral movement the bridge-posts or columns which rest hpon said beams.

Second, in securing the floor-beams to the-lower chords by L-boltshooking through the web of said floorbeams and-passing through the chord-beams and separating-block, so that said parts are securely tied 'and held together, and the load upon the floor-beams fairly transmitted to the chords.

In the accompanying drawings- Figure I is an isometrical perspective of two panels of aniron truss-bridge, showing my improvements and their application.

Figure II is an isometrical perspective of a separating-block for application to I-beams, combined with their flanges in contact. i

Figure III is a cross-section through lower chord, showing separating-block, floor-beams, and L-bolts, asA combined together.

Figures IV, IV, and IV, are isometrica] perspectives of said last-named parts.

Figure V is an isometrical perspective of trussblock.

Figure VI is an isomet'cal perspective of same as combined with chord, diagonal tie-rods, and vertical t8. p0Figure VII is an isometrical view of a section of upper chord, or of a post, column, or other part nnderl compressive strain.

Like letters refer to like parts in each of the figures.

A A represent thc upper chords, and B B, the lower chords; O, the columns or upright posts, all formed ,of I or channel-iron beams, placed side by side.

D 1) represent the diagonal tie-rods, and E, the floor-beams of I-form.

The particular arrangement of the parts is clearly shown in. Fig. I, and the strains to which they are subjected, and the functions which they pertbrm, are too well understood to require special description.

' F represents the separatingLhlock as' applied to the top chords and columns, at a point midway between the ends or points of support thereof, which, bei drawn together by bolts or rivets f', leave the cen with increased cross-sectional dimensions.

The blockl being secured by bolts passing through it and both beams, the column or chord will evidently be materially stifiened, and its liability to give way by iiexure greatly lessened. One, two, or more blocks may be employed, dividing the column into two, three, or more equal parts, according to its length and the requirements of the case.

G G' represent the separating-blocks as applied to Y the chords orl other part receiving transverse strain.

The block G' is madeV to fit the space between the I-beams when they are placed with their flanges in contact, while G' shows the block as made to spread the beams apart to allow the passage of a counter-rod between them.

The blocks are cast with holes g for the passage of bolts t0 tie them and the beams together.

When several of these blocks are placed between a pair of beams, and transverse strain applied to either of said beams, such strain must be transmitted by the blocks to the other beam, and the strain he equally divided between the two.

When the floor-beams are rested upon the iianges -of the inside chord-beams, as shown in Fig. III, the

whole load would rest upon said inside beams, leaving the outside ones entirely free of transverse strain were it not for the introduction of said blocks.

As it is very desirable to so arrange the floor-beams, ghe utility of the arrangement of the blocks is maniest.

H ,H represent L-bolts hooking through the web of `the floor-beam E, (see Fig. 111,) and passinfy through the separating-block G', and drawing the oor-beam tightly to the chord, and causing it to act as a tie to prevent the chords from spreading.

The separating-block may have the holes for the passage of the bolts made as in Fig. IV, which will allow the bolts to pass, one on each side of the floorbeam, to secure the same against turning.

J represents a truss-block, made to fit the space between the chord-beams, the same as blocks G G.

Itis chambe d in the centre to receive the end of the connter- D, through the eye of which, together with those of theoutside ties D', a strong bolt, J', passes.

The chord-beams. being spread for the `passage of the counter-rod, projections K from the truss-block are extended up through the space so formed, and overlapping upon the flanges of the beams, have such contour as to lit the end space of the two columnbeams (l-O, and retain the same against lateral movement upon the chord.

. Having thus described my-improvements,

What I claim, and desireto secure by Letters Patent, is.-

1. The truss-block J with its projections K, when arranged and combined 'with the chords, tie-rods, and columns, as and for the purpose set forth.

2. The bolts H, when combined with the separatingblocks G or G and door-beams I in the manner and for the purpose set forth.

` GEORGE HALSTEAD.

Witnesses:

W. H. Fonnusn, V. H. Brom 

